Process for disproportionating the olefins

ABSTRACT

A process for disproportionating olefins is disclosed which employs a catalyst which includes tungsten and bismuth in the form of oxides or other forms.

United States Patent [191 Fattore et al.

[ Oct. 9, 1973 PROCESS FOR DISPROPORTIONATING THE OLEFINS [75] Inventors: Vittorio Fattore, San Donato Milanese; Marcello Mazzei, Milano; Bruno Notari, Milanese, all of Italy [73] Assignee: Snam Progetti, S.p.A., Milanese,

Italy 22 Filed: Apr. 14,1971 211 Appl. No.: 134,094

[30] Foreign Application Priority Data Apr. 14, 1970 Italy 23269 A/70 [52] U.S. Cl. 260/683 D, 260/668 R, 260/680 R [51] Int. Cl C07c 3/62 [58] Field of Search 260/683 D, 668 R,

Priniary Examiner-Delbert E. Gantz Assistant ExaminerC. E. Spresser Attorney-Ralph M. Watson [5 7] ABSTRACT A process for disproportionating olefins is disclosed which employs a catalyst which includes tungsten and bismuth in the form of oxides or other forms.

11 Claims, No Drawings PROCESS FOR DISPROPORTIONATING THE OLEFINS The present invention provides a process for disproportionating the olefins.

More particularly, the present invention provides a process for disproportionating the olefins by means of a particular catalyst. It is known to disproportionate olefins so that linear olefins are changed into the homologous ones which have a higher carbon atom number and a lower carbon atom number than the starting olefin.

Disproportionating processes are also known according to which use is made of suitable catalyst systems in which, molecular hydrogen is present or absent. However, the known catalysts have the great disadvantage of being very sensitive to poisons and, therefore, have very short life.

An activation step is also carried out inorder to optimize the service of the catalyst. it is based on particular techniques, that are very difficult and often very expensive, which affect the course and the cost of the process.

For example the known catalysts have to be heated at high temperature in presence of air, an inert gas or a reducing gas.

Another drawback one may encounter when employing the known catalyst systems consists of the several regenerations and activations following the starting activation. Multiple regenerations are absolutely necessary because of the very fast decline of the optimum activity owing to the very high amount of carbon which is formed during the course of the process.

The regeneration is generally carried out at a temperature higher than the operating temperature and, therefore, does not allow a continuous running of the process. if the disproportionating reaction is carried out in presence of molecular hydrogen, a very high percentage of the formed olefins is hydrogenated to the corresponding saturated compounds.

it has now been found, and is the object of the present invention,.that the olefins may be disproportionated with high conversion and selectivity by employing a particular catalyst based on tungsten and bismuth oxides, particularly based on bismuth tungstate, some other oxides being present or absent.

The use of this catalyst is very advantageous with respect to the known ones. In fact, it requires neither any starting activation nor subsequent activation and may be employed without being regenerated up to-90 hours, the final carbon deposit being lower than 25%. After this, a simple regeneration in presence of air at working temperature completely restores the starting activity. Moreover, it drasticly lowers the time necessary to reach the best obtainable conversion.

The catalyst'according to the present invention presents a very high working uniformity, from the lowest to the highest percentages of active catalyst.

Another advantage consists of a higher resistance to poisons. According to the process of the present invention, the olefins are disproportionated when being contacted by a catalyst consisting essentially of bismuth and tungsten oxides, particularly of bismuth tungstate with the aforementioned oxides being present or absent, the catalyst being preferably supported and the Bi/W ratios ranging from 1/3 to /1 and preferably at a Bi/W ratio of 2/3.

It has been shown that, in the said range, increasing the amount of bismuth lowers the reaction induction time and increases the resistance to poisons.

The support preferably employed is silica; however, use may be made of other supports as alumina, silicaalumina, kieselguhr and the like.

The reaction may be applied to single olefins or to mixtures of olefins having a carbon atom number ranging between 3 and 30, preferably between 3 'and 12.

For example, it is possible to disproportionate olefins selected among propylene, l-butene, isobutene, lpentene, 2-pentene, l-hexene, Z-heptene, 3-heptene, l-octene, 2-nonene, l-dodecene, 2-tetradecene, lhexadecene, Z-methyl-l-butene, 2-methyl-2-butene, 3-methyl-l-butene, l-phenylbutene-2 and 3-eicosene.

The catalyst of the process according to the present invention may be obtained by inserting into the aforesaid supports suitable compounds of bismuth and tungsten according to the usual method, for example, by impregnation, by coprecipitat'ing or by atomization. The catalyst may be employed in the form of dust, granules, films, little spheres of any form suitable to the employed contact technique.

The disproportionating process of the olefins is carried out at a temperature ranging between 400 and 700C, preferably between 450 and 600C., and at a pressure ranging between 1 and 50 atmospheres. The

disproportionating reaction may be carried out by a continuous or a discontinuous flow system in a fixed or a moving bed, or by means of some other contact methods known to those skilled in the art. The contact time is selected with respect to the working conditions, said contact time being the ratio between the volume of the catalyst bed and the flow rate of the reactants as gases in the reaction conditions: lengthy contact times are generally avoided in order to prevent secondary reac tions from happening. So, use will be made of contact times ranging between 0.1 and 60 seconds. Some other working characteristics will be pointed out by the following unrestrictive examples hereinafter reported to illustrate the invention. The examples 1, 2 and 3 are reported only by a comparative point of view. In all examples, the term selectivity and conversion have the following meanings:

Moles of olefins entering moles of olefins coming out O0 Moles of olefins entering 1 Conversion Percent b.w. of the product Percent b.w. of the converted Selectivity EXAMPLE 1 TABLE I TIME lst Hour 2nd Hour 3rd Hour Product analysis b.w. b.w.

C 11 7.7 6.4 5.0 C l-1,, 0.7 0.7 0.7 C 11 79.5 82.3 86.2 C 11, 0.1 0.1 0.1 l C,H, 2.0 1.6 1.0 2 C.H trans 6.7 5.8 4.4 2 C H, cis 3.2 3.0 2.4 72. conv. 19.7 16.8 12.9

EXAMPLE 2 Propylene was disproportionated in presence of a 10 catalyst consisting of W on silica as a catalyst carrier, the percentage of the activated part being 35.5%. The reaction was carried out at 550C., at atmospheric pressure and at a propylene flow of 30 cc/min. The results are reported in Table 11.

The reaction being ended, the amount of the carbon deposited on the catalyst was calculated by gravimetric way: it was equal to 56.6% b. w. with respect to the catalyst weight.

EXAMPLE 4 21.3 g of Bi (N09 H O were dissolved into 12 cc 15 of water and 2 cc of HNO at 68%. Another solution TABLE 11 Time 1.00 18.00 24.00 31.00 91.00 98.00 98% 99 Analysis of the products as percent by weight:

CgH. 0.5 2.4 3.3 3.9 8.6 9.1 7.8 7.8 CsHsCO: 0.5 0.3 0.4 0.4 0.4 0.4 0.4 0.4 CziHs 97.0 92.5 90.9 88.6 80.0 75.3 78.2 78.3

CJHIO ICJH)! 0.3 1.0 1.2 1.5 2.4 2.7 2.2 2.2 2CtHt trans 0.4 1.7 2.0 2.9 6.1 6.7 5.8 5.8 2C4H Cis 0.4 1.4 1.7 2.2 2.0 5.5 4.9 4.9 CSH 0.3 0.3 Percent conversion 2.2 6.7 8.3 10.5 19.1 23.9 20.9 20.9

EXAMPLE 3 was prepared containing 11 g of 5 (NI-1 0 1 2W() Propylene was disproportionated in presence of a catalyst consisting of WO on silica as catalyst carrier, the percentage of the actived part being 7.6% with respect to l g of sample.

The catalyst was obtained by co-precipitating a solution comprising 5.6 g of 5 (N l-1.9 0.12 WQ SHQ into TABLE 111 Time as hours A 4 1% 6 A Analysis of the products as by weight: 1

051-1 0 into cc of H 0 and 7 cc of H 0 It was stirred up to a complete dissolution of tungstate. The two solutions were joined and stirred in order to favor the formation'of bismuth tungstate. g. of colloidal silica Ludox of the type SM-30 (30% of SiO- the dimensions of particles being 7 mg.) were added and the obtained mixture was stirred up to the homogeneity of the suspension. It was dried on a hot plate under stirring at C, then was calcined at 550C. for 4 hours and was slowly cooled. After cooling, the sample was reduced to particles having 45-70 mesh dimensions, it being ready to the disproportionating reaction.

EXAMPLE 5 The reaction was carried out in presence of a catalyst having a Bi:W ratio of 1:3 (14.68% of B1 0 34% of W0 51.30% of SiO and obtained according to the preceding example. A propylene flow was passed over this catalyst at atmospheric pressure, at a temperature of 550C. and a 30 cc/min rate. The results are reported in Table IV.

TABLE IV Time as hours Analysis of the products as percent by -1- N'- 2C H trans ZCqHn cis CEH 11) Percent conversion EXAMPLE 6 It was worked in presence of a catalyst on silica as a catalyst carrier having a Bi:W ratio of 2:3 (16.8% of Bi O 20.0% of W 63.2% of SiO A propylene flow was sent on this catalyst at atm0 spheric pressure, at a temperature of 550C. and at a rate of 30 cc/min. for the first hours, and 150 cc/min. for the next hours. The resultsare reported in Table V.

The example was performed by working in presence of a catalyst having a Bi:W atomic ratio of 1:1 on 60% of silica as catalyst carrier, the catalyst being obtained according to Example 4. A continuous propylene flow wasted on 1 g of the aforesaid catalyst at atmospheric pressure, 550C. and at a cc/min. rate. The obtained results are reported in Table V1.

TABLE VI Time as hours 1 2 34 3 V4 8 V4 Analysis of the products as by weig C,l-1 14.2 17.9 16.0 18.6 C,H,,-+-CO 1.7 1.7 2.2 2.3 C l-'1 66.1 55.1 57.0 53.8 (2 H 0.4 0.5 0.5 0.6 1 C.H,, 2.2 3.1 3.0 4.3 2 CH, 10.4 12.3 11.6 11.2 2 C 11,. cis 7.9 8.8 8.7 8.2 Z conversion 37.0 44.1 42.1 45.3

EXAMPLE 8 By working in the same conditions of the preceding example, propylene was disproportionated in presence of a catalyst previously actived in situ by air at 550C. for 5 hours. The results. are reported in Table VII.

TABLE VII Time as hours 16 l 1 V1 2 2 34 Analysis of the products as by weig C 11 1.0 5.0 12.8 15.7 16.9 C H +CO, 1.6 1.5 1.5 1.5 1.4 C H, 95.0 84.7 64.8 58.5 55.4 C H 0.3 0.3 0.4 0.4 0.4 1 CH 0.2 0.7 1.8 2.3 2.5 2 C H 0.7 3.6 9.9 12.1 13.1 2 C H cis 0.6 3.3 8.0 9.0 9.6 conversion 4.1 14.4 34.3 40.6 43.7

The obtained results were compared with the ones obtained by employing the same unactivated catalyst and by working in the same conditions (on Table V1); the comparison showed that this catalyst did not need any activation.

EXAMPLE 9 Three tests were carried out by working with a catalyst consisting of wo on 7.6% of silica as catalyst carrier, and with two catalysts consisting of Bi and W, having the following Bi:W ratios:

Bi W 2:3 on 63.2% of Si0 Bi W 1:1 on 62.6% of SiO These tests were carried out on 1 g of catalyst, by feeding airless propylene at atmospheric pressure and at 550C. and at a 30 cc/min. rate. The results are reported on the tables.

TABLE V111 (cat. 7.58 of W0 on silica) Time as hours A 1.40 5.20 7.00 7 A 23.00 Analysis of the products as by weight: C 11. 1.0 4.5 6.5 6.7 5.6 4.6 C l-1 0.1 0.3 0.4 0.4 0.4 04 C ll 94.4 87.1 81.7 81.0 81.5 86.2 1 C H 0.2 0.3 0.5 0.5 0.5 0.5 2 C H trans 2.2 4.0 5.6 5.8 5.7 4.5 2 C 11, cis 2.0 3.6 5.0 5.2 5.1 3.4 conversion 4.8 12.1 17.1 18.2 17.7 12.9

TABLE IX (cat. Bi W 2:3 on silica) Time as hours 1% 1.00 2 lo 6.00 13.10 15.40 Analysis of the products as by weight: C 11, 4.0 5.3 10.1 8.5 9.6 9.6 C ll; 0.4 0.4 0.6 V 0.4 0.4 0.5 C H, 88.4 84.9 75.9 76.4 73.5 73.0 1 C H 1.6 2.1 3.5 3.0 3.0 2.9 2 C l-l trans 2.9 3.9 6.7 6.2 7.1 7.2 2 C H,, cis 2.4 3.3 2.0 4.9 5.7 6.1 C 11 0.44 0.5 0.5 conversion 10.8 14.2 22.3 22.8 25.7 26.1

TABLE X (cat. Bi W 1 1 on silica) Time as hours b 1 16 Analysis of the products as by weight: C,H 1.5 3.8 7.7 C 11, 1 0.9 0.9 0.9 1.0 C l-1 95.4 88.9 78.2 I 67.0 1 C 11; trace 0.1 0.3 0.6 2 C 11, trans 1.1 3.2 6.9 10.6 2 C H cis 1.0 2.9 5.9 8.7 conversion 3.8 10 24 21.0 32.2

By comparing the above data, it will be appreciated that the resistance to water increases, as the amount of bismuth in the bismuth tungsten catalyst is increased.

EXAMPLE 10 TABLE X1 Analysis of the products as by weight:

C 11 2.6 CaHg 2.9 CJ-l 3 .0 a 19.0 C H 7.5 C 11 8.8 a is 34.2

olefins having a carbon atom number higher than 8 21.7

EXAMPLE 11 The example was performed by working in presence of the same catalyst as Example 9. A mixture of propylene and nitrogen (11% and 89% by moles) was fed at a temperature of 550C., a pressure of 20 Kg/cm and product is reported in Table Xll.

TABLE Xll Analysis of the products as by weight:

olefins having a carbon number atomhigher than 4 traces Conversion 48.5

What we claim is: 1 1. A process for the disporportionation of an olefin having from three to 30 carbon atoms or a mixture of said olefins which comprises passing a feed which consists essentially of said olefin or a mixture ofsaid olefins over a catalyst supported by a catalyst carrier, said catalyst being selected from the group consisting of l. bismuth tungstate,

2. a mixture of bismuth oxide and tungsten oxide,

3. a mixture of bismuth tungstate and either tungsten oxide or bismuth oxide; and 4. a mixture of bismuth tungstate with tungsten oxide and bismuth oxide, at a pressure of from l to 50 atmospheres anda contact time of 0.1 to seconds and thereafter recovering the reaction products.

2. A process as defined in claim 1 wherein said catalyst comprises bismuth tungstate.

3. A process as defined in claim 1 wherein the ratio of bismuth to tungsten is in the range of 1:3 to 5:1.

4. A process as defined in claim 3 wherein the ratio of bismuth to tungsten is from 2:3.

5. A process as defined in claim 1 where said catalyst carrier is selected from the group consisting of silica, silica-alumina and kieselguhr.

6. A process as defined in claim 1 wherein said catalyst carrier is silica.

7. A process as defined in claim 1 wherein the disproportionation is carried out at a temperature ranging from 450 to 500C.

8. A process as defined in claim 1 wherein the disproportionation is carried out at atmospheric pressure.

9. A process as defined in claim 1 wherein the olefin is a olefin having from three to 12 carbon atoms.

10. A process as defined in claim 1 wherein the olefin is propylene.

l l. A process as defined in claim 1 wherein the olefin is l-pentene. 

2. a mixture of bismuth oxide and tungsten oxide,
 2. A process as defined in claim 1 wherein said catalyst comprises bismuth tungstate.
 3. A process as defined in claim 1 wherein the ratio of bismuth to tungsten is in the range of 1:3 to 5:1.
 3. a mixture of bismuth tungstate and either tungsten oxide or bismuth oxide; and
 4. a mixture of bismuth tungstate with tungsten oxide and bismuth oxide, at a pressure of from 1 to 50 atmospheres and a contact time of 0.1 to 60 seconds and thereafter recovering the reaction products.
 4. A process as defined in claim 3 wherein the ratio of bismuth to tungsten is from 2:3.
 5. A process as defined in claim 1 where said catalyst carrier is selected from the group consisting of silica, silica-alumina and kieselguhr.
 6. A process as defined in claim 1 wherein said catalyst carrier is silica.
 7. A process as defined in claim 1 wherein the disproportionation is carried out at a temperature ranging from 450* to 500*C.
 8. A process as defined in claim 1 wherein the disproportionation is carried out at atmospheric pressure.
 9. A process as defined in claim 1 wherein the olefin is a olefin having from three to 12 carbon atoms.
 10. A process as defined in claim 1 wherein the olefin is propylene.
 11. A process as defined in claim 1 wherein the olefin is 1-pentene. 